Aluminium tube weight calculator
Round tube in aluminium alloy: 10 common sizes with the mass per metre, and a calculator for your own. Aluminium weighs under 35 % of the steel of the same section.
Common sizes and mass per metre
| Size, mm | Cross-section, mm² | kg/m |
|---|---|---|
| 12×1 | 35 | 0.09 |
| 16×1.5 | 68 | 0.18 |
| 20×2 | 113 | 0.31 |
| 25×2 | 145 | 0.39 |
| 30×2 | 176 | 0.48 |
| 35×2 | 207 | 0.56 |
| 40×2 | 239 | 0.64 |
| 50×3 | 443 | 1.20 |
| 60×3 | 537 | 1.45 |
| 80×3 | 726 | 1.96 |
Where the number comes from
The cross-section works out as F = π/4 · (D² − (D − 2t)²). For 35×2 mm that is 207 mm², which at a density of 2.70 g/cm³ gives 0.56 kg/m.
Aluminium is welded with TIG on alternating current or with a wire feeder and aluminium wire; the oxide film melts at around 2050 °C, far above the metal itself, and has to come off with a stainless brush immediately before welding. The detail is in welding aluminium.
Frequently asked questions
Does the alloy change the weight?
Barely. The density of aluminium alloys runs between 2.66 and 2.80 g/cm³, and trade calculations use 2.70. Across a whole pallet the difference is smaller than the rolling tolerance, so 2.70 is enough for quoting and haulage.
Why does this differ from the weight at the stockist?
Because the dimensional tolerance works both ways, and sheet and section rarely come out at exactly the nominal thickness. On a thin wall the gap reaches a few per cent — order by the tonne with a margin.
Updated: